JP3284948B2 - Strip meandering control method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generally relates to a meandering control method for a strip rolled by a cold rolling mill,
The present invention relates to optimization of a difference (leveling) between left and right roll gaps.

[0002]

2. Description of the Related Art Conventionally, a method of controlling the leveling of a stand of a multi-high rolling mill according to the following equation (1) has been known in order to prevent meandering of a rolled material. ΔT _{i, i + 1} = AΔS _li + BΔW + CΔC (1) where ΔT _{i, i + 1 is} the i-th stand front differential tension, Δ
S _li : i-th stand leveling amount, ΔW: deviation amount in the width direction of the plate, ΔC: crown difference in the width direction of the plate, A, B,
C: Constant Determined by Rolling Schedule An example of performing rolling based on the above equation (1) will be described with reference to FIG. In FIG. 3, 1 is a rolling mill, 2 is a rolled material, 3
Is a rolling direction, 4 is a tension meter, 5 is a meandering correction device, 6 is a leveling device, 7 is a differential tension signal, and 8 is a bias device. The differential tension ΔT _{i, i + 1} is detected from the front tensiometer 4. The differential tension is obtained by measuring the tension at both ends (driving side and operating side) of a strip and measuring the difference. ΔW is detected by a CPC device (not shown) installed behind the mill, ΔC is detected by a crown meter (not shown) installed behind the mill, and BΔW +
With CΔC as the output of the bias signal device 8, AΔS _li =
ΔS _li is obtained from ΔT _{i, i + 1} − (BΔW + CΔC),
This signal is input to the meandering correction device 5 to control leveling.

However, the prior art described above has a problem to be improved in that no consideration is given to the effects of stands other than the i-th stand, and the actual state of rolling is not necessarily reflected.

Therefore, in Japanese Patent Application Laid-Open No. 63-188415, in controlling the leveling of the ith stand, not only the ith stand, but also the forward differential tension of the (i + 1) th stand, the amount of displacement of the strip in the width direction, and the A technique is disclosed in which a crown difference in the width direction is detected, and the leveling amount in the i-th stand is controlled based on the difference.

[0005]

However, Japanese Patent Application Laid-Open No. 63-188
In Japanese Patent Publication No. 415, as a meandering control method, an optimum leveling value is estimated by an evaluation formula based on a difference between the front and rear tensions and a meandering amount, and feedback control of the leveling is performed. Since the relationship between the tension and the leveling is not a linear relationship, there is a problem in the accuracy of the evaluation formula, and it is necessary to improve the evaluation method of the optimum leveling value.

Also, since the amount of meandering is measured by a CPC device behind the mill and is only reflected on leveling, it has been difficult to control meandering accurately. An object of the present invention is to measure a leveling setting failure position of a cold rolling mill, perform high-precision measurement without being affected by the use environment such as fumes and coolant, and improve the conventional method for evaluating an optimal leveling value. To provide a meandering control method.

[0007]

In order to solve the above problems and achieve the object, the present invention uses the following means. (1) The control method of the present invention is a method of controlling meandering of a strip rolled by a cold rolling mill having a plurality of stands, wherein the plate of the strip is detected by an electromagnetic type position detector installed on an arbitrary stand exit side. Measuring the width and meandering amount, and measuring the sum tension and differential tension of the strip with a tension meter installed on the stand exit side, and controlling the leveling of the stand based on these measured values; Measuring the amount of meandering of the strip by a position detector of an electromagnetic type installed on the entrance side of the stand, and controlling the uncoiler position based on the measured value. It is. (2) In the control method of the present invention, the step of controlling the leveling of an arbitrary stand is performed based on the leveling setting defect position ε calculated by solving the simultaneous equations shown in the following equations (1) to (4). This is the strip meandering control method described in the above (1).

[0008]

(Equation 2)

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The present inventor performs high-precision measurement of the leveling setting failure position of a cold rolling mill without being affected by the use environment such as fumes and coolants.
Intensive research has been conducted on a strip meandering control method that improves the conventional method of evaluating the optimum leveling value.

As a result, it is effective to use an electromagnetic type sensor as a position detector in order to eliminate the influence of the use environment such as fumes and coolant on the measurement accuracy. It was found that estimating the leveling setting error position from the differential tension, the sheet width, and the meandering amount, and simultaneously using centering on the entry side of the rolling mill is effective for highly accurate estimation of the leveling setting error position. .

Based on this finding, the inventor of the present invention made the position detector an electromagnetic type sensor, estimated the leveling setting failure position from the sum tension, differential tension, plate width and meandering amount of the strip, and at the same time, A meandering control method for a strip according to the present invention has been found which can prevent meandering due to improper leveling setting by using centering at the entrance side, and completed the present invention.

That is, the present invention specifies a meandering control condition of a strip within the following range, thereby measuring a leveling setting failure position of a cold rolling mill with high accuracy which is not affected by a use environment such as fumes and coolant. By performing the measurement, it is possible to obtain a strip meandering control method which improves the conventional method for evaluating the optimum leveling value.

The reasons for limiting the strip meandering control conditions of the present invention will be described below. (1) Strip meandering control method In a method for controlling strip meandering in a cold rolling mill having a plurality of stands, a position detection of an electromagnetic type installed at an exit side of an arbitrary stand (including a first stand). The width and meandering amount of the strip are measured by a vessel, and the sum tension and the differential tension of the strip are measured by a tensiometer installed on the exit side of the stand.

These measured values are inputted to a computing unit, and a leveling setting fault position ε is obtained by solving the simultaneous equations shown in the above equations (1) to (4). The level of the leveling correction is calculated by estimating the shape of the plate.

The amount of leveling correction is output to the leveling device of the stand, and feedback control is performed so that the amount of leveling correction becomes zero. Further, the meandering amount measured by the position detector installed on the first stand entrance side is input to the arithmetic unit, and the correction amount of the position of the uncoiler is calculated. The uncoiler position correction amount is output to the uncoiler shift device, and feedback control is performed so that the uncoiler position correction amount becomes zero.

At this time, by using an electromagnetic type position detector which is excellent in environment resistance, the influence on the measurement accuracy of fumes, coolants and the like is eliminated. In addition, the reason for performing the uncoiler position control together with the leveling control of each stand is that the estimation accuracy of the plate shape caused by the leveling setting failure increases according to the meandering amount, so that the estimation accuracy of the leveling setting failure position is increased. This is because it is necessary to minimize the meandering amount detected on the rolling mill entrance side by a centering device (uncoiler shift device) on the rolling mill entrance side.

Further, the simultaneous equations shown in the above equations (1) to (4) are used to calculate the strip width (W) and the meandering amount (b) of the strip and the distribution of the tension (T _t ) as shown in FIG. The relationship is established based on the relationship, the actual measured strip width, the meandering amount, the sum tension and the difference tension are input, and by solving these simultaneous equations, the leveling setting error position ε is obtained to obtain the conventional value. Based on the front / rear differential tension and the meandering amount, it is possible to improve the evaluation accuracy of an arbitrary stand leveling amount.

As described above, according to the strip meandering control method of the present invention, it is possible to measure the leveling setting defect position with high accuracy without being affected by the use environment such as fumes and coolant. The meandering of the strip can be prevented.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS With reference to FIG. 1, an embodiment of a strip meandering control method according to the present invention will be described. In FIG. 1,
3 are indicated by the same reference numerals as in FIG. The tension meter 4 installed on the exit side of the i-th stand measures the sum tension and the differential tension of the strip 2, and the position detector 50 measures the width and meandering amount of the strip 2. Here, the position detector 50 is an electromagnetic type sensor, but if environmental measures are sufficiently taken, an optical type sensor can be used.

The measured values of the sum tension, difference tension, plate width, and meandering amount of the strip 2 are input to a calculator 60, and the plate width (W), meandering amount (b), and tension (T _t ) shown in FIG. ) By solving the simultaneous equations shown in the following equations (1) to (4) based on the relationship with the distribution, the plate shape caused by the leveling failure is estimated, and the leveling setting failure position ε is calculated.

[0021]

(Equation 3)

Here, f (x) and g (x) are functions that are determined in advance so as to show their characteristics, and examples of the influence coefficient functions collected in actual rolling are shown below. f (x) = α · x, g (x) = β · x + γ · x ³ (α,
β, γ: constant) The leveling correction amount is calculated from the leveling setting failure position calculated based on the above equation, and the leveling correction amount is output to the leveling device 6 of the i-th stand, and the leveling correction amount is 0.
Feedback control is performed so that

Here, since f (x) and g (x) include terms of the same order, their estimation errors affect each other. Therefore, it is necessary to minimize the influence of g (x) in advance. Then, it is necessary to improve the leveling accuracy relating to f (x).

For this purpose, the meandering amount measured by the position detector 50 installed in front of the first stand is input to the calculator 60, and the correction amount of the uncoiler position is calculated. The uncoiler position correction amount is output to the uncoiler shift device 70, and feedback control is performed so that the uncoiler position correction amount becomes zero.

[0025]

According to the present invention, the meandering detection condition and the control condition of the strip rolled by the cold rolling mill are specified, so that the leveling setting failure can be made without being affected by the use environment such as the fume and the coolant. The position can be measured with high accuracy, and the meandering of the strip due to the improper leveling setting can be prevented.

[Brief description of the drawings]

FIG. 1 is a schematic diagram for explaining a meandering control method of a strip according to an embodiment of the present invention.

FIG. 2 shows a strip width (W) of a strip according to an embodiment of the present invention.
And a diagram showing the relationship between the meandering amount (b) and the tension (T _t ) distribution.

FIG. 3 is a schematic diagram for explaining a conventional strip meandering control method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Rolling machine 2 ... Rolled material (strip) 3 ... Rolling direction 4 ... Tensiometer 5 ... Meandering correction device 6 ... Leveling device 7 ... Differential tension signal 8 ... Bias signal device 50 ... Position detector 60 ... Calculator 70 ... Uncoiler Shift device

Claims (2)

(57) [Claims] 1. A method for controlling meandering of a strip rolled by a cold rolling mill having a plurality of stands, comprising: detecting a strip width and meandering amount of a strip by an electromagnetic type position detector installed at an arbitrary stand exit side. Measure, and measure the sum tension and differential tension of the strip with a tensiometer installed on the stand exit side, based on these measured values,
Controlling the leveling of the stand, measuring the amount of meandering of the strip by an electromagnetic type position detector installed on the first stand entry side, and controlling the uncoiler position based on the measured value. A meandering control method for a strip, comprising: 2. The method according to claim 1, wherein the step of controlling the leveling of the stand is performed based on a leveling setting error position ε calculated by solving simultaneous equations shown in the following equations (1) to (4). Control method of strip meandering. (Equation 1)